Original Article
Early Diet and General Cognitive Outcome at Adolescence in Children Born at or Below 30 Weeks Gestation

https://doi.org/10.1016/j.jpeds.2009.02.030Get rights and content

Objective

To test the hypothesis that effects of early diet on cognition observed at age 8 years persist in adolescents born preterm at ≤ 30 weeks gestational age.

Study design

A subgroup from a preterm infant cohort recruited for a randomized trial studying the effects of early dietary intervention was assessed at age 16 years. IQ scores were compared between those assigned a high-nutrient diet (n = 49) or standard-nutrient diet (n = 46) in infancy at both 8 and 16 years.

Results

At age 8 years, the high-nutrient group had higher mean Verbal IQ (VIQ; P = .03), Performance IQ (P = .01), and Full-Scale IQ (P = .02) scores compared with the standard-nutrient group; the VIQ difference persisted at adolescence (P = .02). This effect was accounted for principally by a significant difference in the mean Verbal Comprehension Index score (P < .008).

Conclusions

A brief period of dietary intervention after preterm birth, principally between 26 and 34 weeks of gestation, affected IQ at age 16 years. A standard-nutrient diet was associated with lower VIQ, accounted for mainly by differences in verbal comprehension, which persisted after control of social factors.

Section snippets

Methods

The original study comprised 2 parallel trials. In study 1, infants (260 males and 242 females) were allocated to a preterm formula (PTF) enriched in protein, energy, minerals, and micronutrients (designated the high-nutrient diet) or banked expressed unfortified donor breast milk (BBM; designated the standard diet). In study 2 (203 males and 221 females), the dietary comparison was between a standard infant formula suitable for full-term infants (TF; designated the standard diet) and PTF.

Results

Baseline neonatal data for the 8-year total group and the subgroup are reported in Table I. Comparison between high and standard-nutrient diet groups at each age revealed no significant differences between any variables in the 8-year total group but a significant difference in GA in the subgroup (mean difference, 0.53 weeks; 95% confidence interval [CI] = −0.98 to −0.06; P < .03). We also compared the 95 children in the subgroup with the 141 members of the 8-year total group not assessed at

Discussion

The most striking aspect of our findings is that a short period of dietary intervention after preterm birth is related to significant effects on intelligence scores at adolescence. Although this is consistent with previous follow-ups of this cohort into childhood, the study of Walker et al16 on the nutritional supplementation of stunted children recruited between age 9 and 24 months demonstrated an effect on cognition in early childhood that was not detected at age 11 to 12 years, despite a

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  • Cited by (0)

    Farley Health Products (now a division of HJ Heinz Co Ltd) collaborated on the original study, supplying the trial formulas as well as contributory funding. The Medical Research Council provided financial support throughout. Neither financial supporter had any role in the design, conduct, analysis or reporting of this study, however. The authors declare no conflicts of interest.

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